Added guide on how to contribute (#119)

Author: ewu63

.github/PULL_REQUEST_TEMPLATE.md

@@ -19,6 +19,7 @@ Explain the steps needed to test the new code to verify that it does indeed addr
 ## Checklist
 _Put an `x` in the boxes that apply._
 
+- [ ] I have run `flake8` and `black` to make sure the code adheres to PEP-8 and is consistently formatted
 - [ ] I have run unit and regression tests which pass locally with my changes
 - [ ] I have added new tests that prove my fix is effective or that my feature works
 - [ ] I have added necessary documentation

doc/contribute.rst

@@ -0,0 +1,48 @@
+How to Contribute to pyOptSparse
+================================
+pyOptSparse is an open-source tool, thus we welcome users to submit additions or fixes to the code to make it better for everybody.
+
+Issues
+------
+If you have an issue with pyOptSparse, a bug to report, or a feature to request, submit an issue on the GitHub repository.
+This lets other users know about the issue.
+If you are comfortable fixing the issue, please do so and submit a pull request.
+
+Coding style
+------------
+We use `black <https://github.com/psf/black>`_ for formatting.
+Please install it following its documentation, and run it with the command line argument ``-l 120``, for example at the project root directory::
+
+    black . -l 120
+
+This will automatically format all Python files.
+
+We use `flake8 <https://flake8.pycqa.org/en/latest/>`_ for linting.
+Please install it following its instructions, and run it at the project root with::
+
+    flake8 .
+
+which will use the ``.flake8`` configuration file provided by pyOptSparse.
+
+For an easier workflow, we recommend integrating these tools with your code editor.
+
+.. warning::
+    For a PR to be accepted, it must pass all GitHub checks, which include both formatting checks with ``black`` and syntax checks with ``flake8``.
+
+Documentation
+-------------
+When you add or modify code, make sure to provide relevant documentation that explains the new code.
+This should be done in code via docstrings and comments, but also in the Sphinx documentation as well if you add a new feature or capability.
+Look at the ``.rst`` files in the ``doc`` section of the repo.
+
+Testing
+-------
+When you add code or functionality, add tests that cover the new or modified code.
+These may be units tests for individual components or regression tests for entire models that use the new functionality.
+All the existing tests can be found under the ``test`` folder.
+
+Pull requests
+-------------
+Finally, after adding or modifying code, and making sure the steps above are followed, submit a pull request via the GitHub interface.
+This will automatically go through all of the tests in the repo to make sure everything is functioning properly.
+The main developers of pyOptSparse will then merge in the request or provide feedback on how to improve the contribution.

doc/index.rst

@@ -1,17 +1,8 @@
-.. pyOptSparse documentation master file, created by
-   sphinx-quickstart on Sat Dec  7 13:50:49 2013.
-   You can adapt this file completely to your liking, but it should at least
-   contain the root `toctree` directive.
-
-.. _pyoptsparse:
-
 ===========
 pyOptSparse
 ===========
-
-PYthon OPTimization (Sparse) Framework
-
-`pyOptSparseSparse` is a replacement for pyOpt.
+pyOptSparse is an object-oriented framework for formulating and solving nonlinear constrained optimization problems in an efficient, reusable, and portable manner.
+It is a fork of pyOpt that uses sparse matrices throughout the code to more efficiently handle large-scale optimization problems.
 
 .. toctree::
    :maxdepth: 2
@@ -24,3 +15,4 @@ PYthon OPTimization (Sparse) Framework
    optimizers
    reference
    postprocessing
+   contribute